Sodium metabisulfite

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Sodium metabisulfite
Sodium metabisulfite.jpg
Sodium-metabisulfite-2D.png
Names
Other names
  • Sodium pyrosulfite
  • Sodium disulfite
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ECHA InfoCard 100.028.794 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 231-673-0
E number E223 (preservatives)
PubChem CID
RTECS number
  • UX8225000
UNII
  • InChI=1S/2Na.H2O5S2/c;;1-6(2)7(3,4)5/h;;(H,1,2)(H,3,4,5)/q2*+1;/p-2
  • [O-]S(=O)S(=O)(=O)[O-].[Na+].[Na+]
Properties
Na2S2O5
Molar mass 190.107 g/mol
AppearanceWhite to yellow powder
Odor Faint SO2
Density 1.48 g/cm3
Melting point 170 °C (338 °F; 443 K) decomposition begins at 150 °C
  • 45.1 g/100 mL (0 °C)
  • 65.3 g/100 mL (20 °C)
  • 81.7 g 100 mL (100 °C)
Solubility Very soluble in glycerol
Slightly soluble in ethanol
Hazards
GHS labelling:
GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
Danger
H302, H318
P264, P270, P280, P301+P312, P305+P351+P338, P310, P330, P501
NFPA 704 (fire diamond)
NFPA 704.svgHealth 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g. chloroformFlammability 0: Will not burn. E.g. waterInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
2
0
1
NIOSH (US health exposure limits):
PEL (Permissible)
None [1]
REL (Recommended)
TWA 5 mg/m3 [1]
IDLH (Immediate danger)
N.D. [1]
Safety data sheet (SDS) Mallinckrodt MSDS
Related compounds
Other anions
Sodium sulfite
Sodium bisulfite
Other cations
Potassium metabisulfite
Related compounds
 Sodium dithionite
Sodium thiosulfate
Sodium sulfate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Sodium metabisulfite or sodium pyrosulfite (IUPAC spelling; Br. E. sodium metabisulphite or sodium pyrosulphite) is an inorganic compound of chemical formula Na2S2O5. The substance is sometimes referred to as disodium metabisulfite. It is used as a disinfectant, antioxidant, and preservative agent. [2] When dissolved in water it forms sodium bisulfite.

Contents

Preparation

Sodium metabisulfite can be prepared by treating a solution of sodium hydroxide with sulfur dioxide. [3] When conducted in warm water, Na2SO3 initially precipitates as a yellow solid. With more SO2, the solid dissolves to give the disulfite, which crystallises upon cooling. [4]

SO2 + 2 NaOH → Na2SO3 + H2O
SO2 + Na2SO3 → Na2S2O5

which yields a residue of colourless solid Na2S2O5.

Chemical structure

The anion metabisulfite consists of an SO2 group linked to an SO3 group, with the negative charge more localised on the SO3 end. The S–S bond length is 2.22 Å, and the "thionate" and "thionite" S–O distances are 1.46 and 1.50 Å, respectively. [5]

Reactivity

Upon dissolution in water, bisulfite is generated:

Na2S2O5 + H2O → 2 Na+ + 2 HSO3−

Uses

Sodium and potassium metabisulfite have many major and niche uses. It is widely used for preserving food and beverages.

Safety

Sodium metabisulfite, despite not being flammable, decomposes in 150 °C of heat releasing toxic gasses when decomposed. It is corrosive when dissolved in water. Some people who are sulfite sensitive may experience an allergic reaction to sodium meta bisulfite, sometimes severe, resulting in labeling requirements for food safety. [20]

Related Research Articles

<span class="mw-page-title-main">Sulfurous acid</span> Chemical compound

Sulfuric(IV) acid, also known as sulfurous (UK: sulphurous) acid and thionic acid, is the chemical compound with the formula H2SO3.

<span class="mw-page-title-main">Sulfite</span> Oxyanion with a central atom of sulfur surrounded by 3 oxygen atoms

Sulfites or sulphites are compounds that contain the sulfite ion, SO2−
3. The sulfite ion is the conjugate base of bisulfite. Although its acid is elusive, its salts are widely used.

Sulfur trioxide (alternative spelling sulphur trioxide) is the chemical compound with the formula SO3. It has been described as "unquestionably the most [economically] important sulfur oxide". It is prepared on an industrial scale as a precursor to sulfuric acid.

<span class="mw-page-title-main">Sodium sulfite</span> Chemical compound

Sodium sulfite (sodium sulphite) is the inorganic compound with the chemical formula Na2SO3. A white, water-soluble solid, it is used commercially as an antioxidant and preservative. It is also suitable for the softening of lignin in the pulping and refining processes of wood and lignocellulosic materials. A heptahydrate is also known but it is less useful because of its greater susceptibility toward oxidation by air.

<span class="mw-page-title-main">Sulfonic acid</span> Organic compounds with the structure R−S(=O)2−OH

In organic chemistry, sulfonic acid refers to a member of the class of organosulfur compounds with the general formula R−S(=O)2−OH, where R is an organic alkyl or aryl group and the S(=O)2(OH) group a sulfonyl hydroxide. As a substituent, it is known as a sulfo group. A sulfonic acid can be thought of as sulfuric acid with one hydroxyl group replaced by an organic substituent. The parent compound is the parent sulfonic acid, HS(=O)2(OH), a tautomer of sulfurous acid, S(=O)(OH)2. Salts or esters of sulfonic acids are called sulfonates.

In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state converts to two compounds, one of higher and one of lower oxidation state. The reverse of disproportionation, such as when a compound in an intermediate oxidation state is formed from precursors of lower and higher oxidation states, is called comproportionation, also known as symproportionation.

<span class="mw-page-title-main">Vanadium(V) oxide</span> Precursor to vanadium alloys and industrial catalyst

Vanadium(V) oxide (vanadia) is the inorganic compound with the formula V2O5. Commonly known as vanadium pentoxide, it is a brown/yellow solid, although when freshly precipitated from aqueous solution, its colour is deep orange. Because of its high oxidation state, it is both an amphoteric oxide and an oxidizing agent. From the industrial perspective, it is the most important compound of vanadium, being the principal precursor to alloys of vanadium and is a widely used industrial catalyst.

<span class="mw-page-title-main">Sodium dithionite</span> Chemical compound

Sodium dithionite is a white crystalline powder with a sulfurous odor. Although it is stable in dry air, it decomposes in hot water and in acid solutions.

<span class="mw-page-title-main">Bisulfite</span> Chemical compound or ion

The bisulfite ion (IUPAC-recommended nomenclature: hydrogensulfite) is the ion HSO−
3. Salts containing the HSO−
3 ion are also known as "sulfite lyes". Sodium bisulfite is used interchangeably with sodium metabisulfite (Na2S2O5). Sodium metabisulfite dissolves in water to give a solution of Na+HSO−
3.

<span class="mw-page-title-main">Potassium metabisulfite</span> Chemical compound

Potassium metabisulfite, K2S2O5, also known as potassium pyrosulfite, is a white crystalline powder with a pungent odour. It is mainly used as an antioxidant or chemical sterilant. As a disulfite, it is chemically very similar to sodium metabisulfite, with which it is sometimes used interchangeably. Potassium metabisulfite has a monoclinic crystal structure.

<span class="mw-page-title-main">Dithionite</span> Oxyanion of sulfur at the oxidation number +3

The dithionite is the oxyanion with the formula [S2O4]2−. It is commonly encountered as the salt sodium dithionite. For historical reasons, it is sometimes called hydrosulfite, but it contains no hydrogen and is not a sulfite. The dianion has a steric number of 4 and trigonal pyramidal geometry.

<span class="mw-page-title-main">Potassium bisulfite</span> Chemical compound

Potassium bisulfite (or potassium hydrogen sulfite) is a chemical mixture with the approximately correctly mentioned formula chemical formula KHSO3. Potassium bisulfite in fact is not a actual compound, but a mixture of salts that dissolve in water to give solutions composed of potassium ions and bisulfite ions. It is a white solid with an odor of sulfur dioxide. Attempts to crystallize potassium bisulfite yield potassium metabisulfite, K2S2O5.

<span class="mw-page-title-main">Calcium sulfite</span> Chemical compound

Calcium sulfite, or calcium sulphite, is a chemical compound, the calcium salt of sulfite with the formula CaSO3·x(H2O). Two crystalline forms are known, the hemihydrate and the tetrahydrate, respectively CaSO3·½(H2O) and CaSO3·4(H2O). All forms are white solids. It is most notable as the product of flue-gas desulfurization.

<span class="mw-page-title-main">Potassium sulfite</span> Chemical compound

Potassium sulfite is the inorganic compound with the formula K2SO3. It is the salt of potassium cation and sulfite anion. It is a white solid that is highly soluble in water. Potassium sulfite is used for preserving food and beverages.

<span class="mw-page-title-main">Calcium bisulfite</span> Chemical compound

Calcium bisulfite is an inorganic compound which is the salt of a calcium cation and a bisulfite anion. It may be prepared by treating lime with an excess of sulfur dioxide and water. As a food additive it is used as a preservative under the E number E227. Calcium bisulfite is an acid salt and behaves like an acid in aqueous solution. It is used in the sulfite process for producing paper from wood chips.

The Wellman–Lord process is a regenerable process to remove sulfur dioxide from flue gas without creating a throwaway sludge product.

<span class="mw-page-title-main">Disulfite</span> Chemical compound

A disulfite, commonly known as metabisulfite or pyrosulfite, is a chemical compound containing the ion S
2O2−
5. It is a colorless dianion that is primarily marketed in the form of sodium metabisulfite or potassium metabisulfite. When dissolved in water, these salts release the hydrogensulfite HSO−
3 anion. These salts act equivalently to sodium hydrogensulfite or potassium hydrogensulfite.

<span class="mw-page-title-main">Sodium bisulfite</span> Chemical compound

Sodium bisulfite (or sodium bisulphite, sodium hydrogen sulfite) is a chemical mixture with the approximate chemical formula NaHSO3. Sodium bisulfite is not a real compound, but a mixture of salts that dissolve in water to give solutions composed of sodium and bisulfite ions. It appears in form of white or yellowish-white crystals with an odor of sulfur dioxide. Regardless of its ill-defined nature, sodium bisulfite is used in many different industries such as a food additive with E number E222 in the food industry, a reducing agent in the cosmetic industry, and a decomposer of residual hypochlorite used in the bleaching industry.

<span class="mw-page-title-main">Chevreul's salt</span> Chemical compound

Chevreul's salt (copper(I,II) sulfite dihydrate, Cu2SO3•CuSO3•2H2O or Cu3(SO3)2•2H2O), is a copper salt which was prepared for the first time by a French chemist Michel Eugène Chevreul in 1812. Its unusual property is that it contains copper in both of its common oxidation states, making it a mixed-valence complex. It is insoluble in water and stable in air. What was known as Rogojski's salt is a mixture of Chevreul's salt and metallic copper.

The topic of sulfite food and beverage additives covers the application of sulfites in food chemistry. "Sulfite" is jargon that encompasses a variety of materials that are commonly used as preservatives or food additive in the production of diverse foods and beverages. Although sulfite salts are relatively nontoxic, their use has led to controversy, resulting in extensive regulations. Sulfites are a source of sulfur dioxide (SO2), a bactericide.

References

  1. 1 2 3 NIOSH Pocket Guide to Chemical Hazards. "#0566". National Institute for Occupational Safety and Health (NIOSH).
  2. ↑ Barberá, José Jiménez; Metzger, Adolf; Wolf, Manfred (2000). "Sulfites, Thiosulfates, and Dithionitesl Chemistry". Ullmann's Encyclopedia of Industrial Chemistry . Weinheim: Wiley-VCH. doi:10.1002/14356007.a25_477. ISBN   3527306730.
  3. ↑ Catherine E. Housecroft; Alan G. Sharpe (2008). "Chapter 16: The group 16 elements". Inorganic Chemistry, 3rd Edition. Pearson. p. 520. ISBN   978-0-13-175553-6.
  4. ↑ Johnstone, H. F. (1946). "Sulfites and Pyrosulfites of the Alkali Metals". Inorganic Syntheses. Vol. 2. pp. 162–167. doi:10.1002/9780470132333.ch49. ISBN   9780470132333.
  5. ↑ K. L. Carter, T. A. Siddiquee, K. L. Murphy, D. W. Bennett "The surprisingly elusive crystal structure of sodium metabisulfite" Acta Crystallogr. (2004). B60, 155–162. doi : 10.1107/S0108768104003325
  6. 1 2 3 McGee, Douglas L. (2013). "Local and topical anesthesia". In Roberts, James R.; Jerris, R. Hedges (eds.). Roberts and Hedges' Clinical Procedures in Emergency Medicine (6th ed.). Elsevier/Saunders. p. 519. ISBN   9781455748594.
  7. ↑ Niazi, Safaraz K. (2009). Handbook of Pharmaceutical Manufacturing Formulations. Volume 6, Sterile Products (2nd ed.). New York: Informa Healthcare. p. 410. ISBN   9781420081312.
  8. ↑ Barnes, Andrew R. (2013). "Chapter 48. Chemical stability in dosage forms". In Aulton, Michael E.; Taylor, Kevin M.G. (eds.). Aulton's pharmaceutics : the design and manufacture of medicines (4th ed.). Churchill Livingstone/Elsevier. p. 833. ISBN   9780702053931.
  9. ↑ "Ingredients". Summit Brands. 31 October 2019. Retrieved 25 April 2021.
  10. ↑ Anchell, Steve (2008). The darkroom cookbook (3rd ed.). Amsterdam: Focal Press. pp.  193. ISBN   978-0240810553.
  11. ↑ [ dead link ]
  12. ↑ "Color Metallography". 2011-05-04.
  13. ↑ George F. Vander Voort. "ETCHING ISOTHERMALLY TREATED STEELS". Asminternational.org. Archived from the original (PDF) on 16 October 2022. Retrieved 24 January 2022.
  14. ↑ "Micro-Pak Enhanced Packaging Stickers" (PDF). 2020-05-05.
  15. ↑ Sivakumar, D.; Korsten, L. (2020-05-05). "15 - Litchi (Litchi chinensis Sonn.)". Postharvest Biology and Technology of Tropical and Subtropical Fruits. Woodhead Publishing Series in Food Science, Technology and Nutrition. Woodhead. pp. 361–409e. doi:10.1533/9780857092885.361. ISBN   9781845697358.
  16. ↑ Manek, Rahul V.; Builders, Philip F.; Kolling, William M.; Emeje, Martins; Kunle, Olobayo O. (June 2012). "Physicochemical and binder properties of starch obtained from Cyperus esculentus". AAPS PharmSciTech. 13 (2): 379–388. doi:10.1208/s12249-012-9761-z. ISSN   1530-9932. PMC   3364391 . PMID   22350737.
  17. ↑ Nawab, Anjum; Alam, Feroz; Haq, Muhammad Abdul; Hasnain, Abid (2016). "Biodegradable film from mango kernel starch: Effect of plasticizers on physical, barrier, and mechanical properties". Starch - Stärke. 68 (9–10): 919–928. doi:10.1002/star.201500349. ISSN   1521-379X.
  18. ↑ Nyakabau, Tatenda; Wokadala, Obiro Cuthbert; Emmambux, Mohammad Naushad (2013). "Effect of steeping additives on tef starch extraction and its quality". Starch - Stärke. 65 (9–10): 738–746. doi:10.1002/star.201200241. hdl: 2263/41924 . ISSN   1521-379X.
  19. ↑ Park, S. H.; Bean, S. R.; Wilson, J. D.; Schober, T. J. (2006). "Rapid Isolation of Sorghum and Other Cereal Starches Using Sonication". Cereal Chemistry. 83 (6): 611–616. doi:10.1094/CC-83-0611. ISSN   1943-3638.
  20. ↑ "What is Sulfite Sensitivity?".
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